Set the spte before adding it to the rmap of its child so that all parent
spte are valid when propagate unsync bit from a usnync page / children page

And this feature is needed by the later patch

Signed-off-by: Xiao Guangrong <xiaoguangr...@linux.vnet.ibm.com>
---
 arch/x86/kvm/mmu.c         |   74 +++++++++++++++----------------------------
 arch/x86/kvm/mmutrace.h    |    2 +-
 arch/x86/kvm/paging_tmpl.h |   14 +++-----
 3 files changed, 32 insertions(+), 58 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a2d28aa..89202f4 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1321,12 +1321,14 @@ static unsigned kvm_page_table_hashfn(gfn_t gfn)
        return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
 }

-static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
-                                   struct kvm_mmu_page *sp, u64 *parent_pte)
+static void mmu_page_add_set_parent_pte(struct kvm_vcpu *vcpu,
+                                       struct kvm_mmu_page *sp,
+                                       u64 *parent_pte)
 {
        if (!parent_pte)
                return;

+       mmu_spte_set(parent_pte, __pa(sp->spt) | SHADOW_PAGE_TABLE);
        pte_list_add(vcpu, parent_pte, &sp->parent_ptes);
 }

@@ -1357,7 +1359,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct 
kvm_vcpu *vcpu,
        list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
        bitmap_zero(sp->slot_bitmap, KVM_MEM_SLOTS_NUM);
        sp->parent_ptes = 0;
-       mmu_page_add_parent_pte(vcpu, sp, parent_pte);
+       mmu_page_add_set_parent_pte(vcpu, sp, parent_pte);
        kvm_mod_used_mmu_pages(vcpu->kvm, +1);
        return sp;
 }
@@ -1690,13 +1692,10 @@ static void clear_sp_write_flooding_count(u64 *spte)
        __clear_sp_write_flooding_count(sp);
 }

-static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
-                                            gfn_t gfn,
-                                            gva_t gaddr,
-                                            unsigned level,
-                                            int direct,
-                                            unsigned access,
-                                            u64 *parent_pte)
+static struct kvm_mmu_page *
+kvm_mmu_get_set_page(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gaddr,
+                    unsigned level, int direct, unsigned access,
+                    u64 *parent_pte)
 {
        union kvm_mmu_page_role role;
        unsigned quadrant;
@@ -1726,7 +1725,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
kvm_vcpu *vcpu,
                if (sp_is_unsync(sp) && kvm_sync_page_transient(vcpu, sp))
                        break;

-               mmu_page_add_parent_pte(vcpu, sp, parent_pte);
+               mmu_page_add_set_parent_pte(vcpu, sp, parent_pte);
                if (sp_unsync_children_num(sp)) {
                        kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);
                        kvm_mmu_mark_parents_unsync(sp);
@@ -1734,7 +1733,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
kvm_vcpu *vcpu,
                        kvm_mmu_mark_parents_unsync(sp);

                __clear_sp_write_flooding_count(sp);
-               trace_kvm_mmu_get_page(sp, false);
+               trace_kvm_mmu_get_set_page(sp, false);
                return sp;
        }
        ++vcpu->kvm->stat.mmu_cache_miss;
@@ -1754,7 +1753,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct 
kvm_vcpu *vcpu,
                account_shadowed(vcpu->kvm, gfn);
        }
        init_shadow_page_table(sp);
-       trace_kvm_mmu_get_page(sp, true);
+       trace_kvm_mmu_get_set_page(sp, true);
        return sp;
 }

@@ -1807,14 +1806,6 @@ static void shadow_walk_next(struct 
kvm_shadow_walk_iterator *iterator)
        return __shadow_walk_next(iterator, *iterator->sptep);
 }

-static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp)
-{
-       u64 spte;
-
-       spte = __pa(sp->spt) | SHADOW_PAGE_TABLE;
-       mmu_spte_set(sptep, spte);
-}
-
 static void drop_large_spte(struct kvm_vcpu *vcpu, u64 *sptep)
 {
        if (is_large_pte(*sptep)) {
@@ -1879,11 +1870,6 @@ static void kvm_mmu_page_unlink_children(struct kvm *kvm,
                mmu_page_zap_pte(kvm, sp, sp->spt + i);
 }

-static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
-{
-       mmu_page_remove_parent_pte(sp, parent_pte);
-}
-
 static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
        u64 *parent_pte;
@@ -2468,7 +2454,6 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, 
int write,
                        bool prefault)
 {
        struct kvm_shadow_walk_iterator iterator;
-       struct kvm_mmu_page *sp;
        int emulate = 0;
        gfn_t pseudo_gfn;

@@ -2489,16 +2474,9 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, 
int write,

                        base_addr &= PT64_LVL_ADDR_MASK(iterator.level);
                        pseudo_gfn = base_addr >> PAGE_SHIFT;
-                       sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
-                                             iterator.level - 1,
-                                             1, ACC_ALL, iterator.sptep);
-                       if (!sp) {
-                               pgprintk("nonpaging_map: ENOMEM\n");
-                               kvm_release_pfn_clean(pfn);
-                               return -ENOMEM;
-                       }
-
-                       link_shadow_page(iterator.sptep, sp);
+                       kvm_mmu_get_set_page(vcpu, pseudo_gfn, iterator.addr,
+                                            iterator.level - 1,
+                                            1, ACC_ALL, iterator.sptep);
                }
        }
        return emulate;
@@ -2713,8 +2691,8 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
        if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
                spin_lock(&vcpu->kvm->mmu_lock);
                kvm_mmu_free_some_pages(vcpu);
-               sp = kvm_mmu_get_page(vcpu, 0, 0, PT64_ROOT_LEVEL,
-                                     1, ACC_ALL, NULL);
+               sp = kvm_mmu_get_set_page(vcpu, 0, 0, PT64_ROOT_LEVEL,
+                                         1, ACC_ALL, NULL);
                ++sp->root_count;
                spin_unlock(&vcpu->kvm->mmu_lock);
                vcpu->arch.mmu.root_hpa = __pa(sp->spt);
@@ -2725,10 +2703,10 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
                        ASSERT(!VALID_PAGE(root));
                        spin_lock(&vcpu->kvm->mmu_lock);
                        kvm_mmu_free_some_pages(vcpu);
-                       sp = kvm_mmu_get_page(vcpu, i << (30 - PAGE_SHIFT),
-                                             i << 30,
-                                             PT32_ROOT_LEVEL, 1, ACC_ALL,
-                                             NULL);
+                       sp = kvm_mmu_get_set_page(vcpu, i << (30 - PAGE_SHIFT),
+                                                 i << 30,
+                                                 PT32_ROOT_LEVEL, 1, ACC_ALL,
+                                                 NULL);
                        root = __pa(sp->spt);
                        ++sp->root_count;
                        spin_unlock(&vcpu->kvm->mmu_lock);
@@ -2764,8 +2742,8 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)

                spin_lock(&vcpu->kvm->mmu_lock);
                kvm_mmu_free_some_pages(vcpu);
-               sp = kvm_mmu_get_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL,
-                                     0, ACC_ALL, NULL);
+               sp = kvm_mmu_get_set_page(vcpu, root_gfn, 0, PT64_ROOT_LEVEL,
+                                         0, ACC_ALL, NULL);
                root = __pa(sp->spt);
                ++sp->root_count;
                spin_unlock(&vcpu->kvm->mmu_lock);
@@ -2798,9 +2776,9 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
                }
                spin_lock(&vcpu->kvm->mmu_lock);
                kvm_mmu_free_some_pages(vcpu);
-               sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
-                                     PT32_ROOT_LEVEL, 0,
-                                     ACC_ALL, NULL);
+               sp = kvm_mmu_get_set_page(vcpu, root_gfn, i << 30,
+                                         PT32_ROOT_LEVEL, 0,
+                                         ACC_ALL, NULL);
                root = __pa(sp->spt);
                ++sp->root_count;
                spin_unlock(&vcpu->kvm->mmu_lock);
diff --git a/arch/x86/kvm/mmutrace.h b/arch/x86/kvm/mmutrace.h
index 7fe9562..f100078 100644
--- a/arch/x86/kvm/mmutrace.h
+++ b/arch/x86/kvm/mmutrace.h
@@ -145,7 +145,7 @@ TRACE_EVENT(
 );

 TRACE_EVENT(
-       kvm_mmu_get_page,
+       kvm_mmu_get_set_page,
        TP_PROTO(struct kvm_mmu_page *sp, bool created),
        TP_ARGS(sp, created),

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 7dacc80..c79c503 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -503,8 +503,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                sp = NULL;
                if (!is_shadow_present_pte(*it.sptep)) {
                        table_gfn = gw->table_gfn[it.level - 2];
-                       sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1,
-                                             false, access, it.sptep);
+                       sp = kvm_mmu_get_set_page(vcpu, table_gfn, addr,
+                                       it.level - 1, false, access, it.sptep);
                }

                /*
@@ -513,9 +513,6 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                 */
                if (FNAME(gpte_changed)(vcpu, gw, it.level - 1))
                        goto out_gpte_changed;
-
-               if (sp)
-                       link_shadow_page(it.sptep, sp);
        }

        for (;
@@ -533,9 +530,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,

                direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);

-               sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,
-                                     true, direct_access, it.sptep);
-               link_shadow_page(it.sptep, sp);
+               kvm_mmu_get_set_page(vcpu, direct_gfn, addr, it.level - 1,
+                                    true, direct_access, it.sptep);
        }

        clear_sp_write_flooding_count(it.sptep);
@@ -548,7 +544,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,

 out_gpte_changed:
        if (sp)
-               kvm_mmu_put_page(sp, it.sptep);
+               drop_parent_pte(sp, it.sptep);
        kvm_release_pfn_clean(pfn);
        return NULL;
 }
-- 
1.7.7.4

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